Architecture of the ESCPE-1 membrane coat

Recycling of membrane proteins enables the reuse of receptors, ion channels and transporters. A key component of the recycling machinery is the endosomal sorting complex for promoting exit 1 (ESCPE-1), which rescues transmembrane proteins from the endolysosomal pathway for transport to the trans-Golgi network and the plasma membrane. This rescue entails the formation of recycling tubules through ESCPE-1 recruitment, cargo capture, coat assembly and membrane sculpting by mechanisms that remain largely unknown. Herein, we show that ESCPE-1 has a single-layer coat organization and suggest how synergistic interactions between ESCPE-1 protomers, phosphoinositides and cargo molecules result in a global arrangement of amphipathic helices to drive tubule formation. Our results thus define a key process of tubule-based endosomal sorting.

A neurodevelopmental disorder associated with an activating de novo missense variant in ARF1

ADP-ribosylation factor 1 (ARF1) is a small GTPase that regulates membrane traffic at the Golgi apparatus and endosomes through recruitment of several coat proteins and lipid-modifying enzymes. Here, we report a pediatric patient with an ARF1-related disorder because of a monoallelic de novo missense variant (c.296 G > A; p.R99H) in the ARF1 gene, associated with developmental delay, hypotonia, intellectual disability and motor stereotypies. Neuroimaging revealed a hypoplastic corpus callosum and subcortical white matter abnormalities. Notably, this patient did not exhibit periventricular heterotopias previously observed in other patients with ARF1 variants (including p.R99H). Functional analysis of the R99H-ARF1 variant protein revealed that it was expressed at normal levels and properly localized to the Golgi apparatus; however, the expression of this variant caused swelling of the Golgi apparatus, increased the recruitment of coat proteins such as coat protein complex I, adaptor protein complex 1 and GGA3 and altered the morphology of recycling endosomes. In addition, we observed that the expression of R99H-ARF1 prevented dispersal of the Golgi apparatus by the ARF1-inhibitor brefeldin A. Finally, protein interaction analyses showed that R99H-ARF1 bound more tightly to the ARF1-effector GGA3 relative to wild-type ARF1. These properties were similar to those of the well-characterized constitutively active Q71L-ARF1 mutant, indicating that the pathogenetic mechanism of the R99H-ARF1 variant involves constitutive activation with resultant Golgi and endosomal alterations. The absence of periventricular nodular heterotopias in this R99H-ARF1 subject also indicates that this finding may not be a consistent phenotypic expression of all ARF1-related disorders.

DNA damage induced by radiation exposure from cardiac catheterization – an analysis in patients and operators

Background

The biological effects of low-dose radiation from cardiac imaging or intervention remain largely unknown. This study aimed to evaluate the effects of ionized radiation from cardiac catheterization on genomic DNA integrity and inflammatory cytokines in patients and operators.

Methods

Peripheral mononuclear cells (MNCs) were isolated from patients (n=52) and operators (n=35) before and after coronary angiography and/or percutaneous coronary intervention. Expression of gammaH2AX, a marker for DNA double-strand breaks, was measured by immunofluorescence. Dicentric chromosomes (DICs), a form of chromosome aberrations, were assayed using a fluorescent in situ hybridization technique.

Results

In the patient MNCs, the numbers of gammaH2AX foci and DICs increased after cardiac catheterization by 101±75% and 28±99%, respectively (P<0.05 for both). The mRNA expressions of interleukin (IL)-1α, IL-1β, leukemia inhibitory factor (LIF) and caspase-1 were significantly increased by radiation exposure from cardiac catheterization. The increase in IL-1β was significantly correlated with that of gammaH2AX, but not with dose area product. In the operators, neither gammaH2AX foci nor DICs level was changed, but IL-1β mRNA was significantly increased. Protein expression of IkappaBα was significantly decreased in both groups.

Conclusions

DNA damage was increased in the MNCs of patients, but not of operators, who underwent cardiac catheterization. Inflammatory cytokines were increased both in the patients and operators, presumably through activation of NF-kappaB. Further efforts to reduce radiation exposure from cardiac catheterization are necessary both for patients and operators.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grants-in-Aid for Scientific Research (KAKENHI)

The Parkinson's Disease Protein LRRK2 Interacts with the GARP Complex to Promote Retrograde Transport to the trans-Golgi Network

Mutations in Leucine-rich repeat kinase 2 (LRRK2) cause Parkinson's disease (PD). However, the precise function of LRRK2 remains unclear. We report an interaction between LRRK2 and VPS52, a subunit of the Golgi-associated retrograde protein (GARP) complex that identifies a function of LRRK2 in regulating membrane fusion at the trans-Golgi network (TGN). At the TGN, LRRK2 further interacts with the Golgi SNAREs VAMP4 and Syntaxin-6 and acts as a scaffolding platform that stabilizes the GARP-SNAREs complex formation. Therefore, LRRK2 influences both retrograde and post-Golgi trafficking pathways in a manner dependent on its GTP binding and kinase activity. This action is exaggerated by mutations associated with Parkinson's disease and can be blocked by kinase inhibitors. Disruption of GARP sensitizes dopamine neurons to mutant LRRK2 toxicity in C. elegans, showing that these pathways are interlinked in vivo and suggesting a link in PD.

Safety and feasibility of retrograde inoue balloon for balloon aortic valvuloplasty without rapid ventricular pacing during transcatheter aortic valve implantation

Background

Although rapid ventricular pacing (RVP) is commonly performed for preparation of transcatheter aortic valve implantation (TAVI). It has been reported that multiple and / or prolonged RVP is associated with adverse clinical outcomes of TAVI. Retrograde Inoue-Balloon was designed for balloon aortic valvuloplasty (BAV) without RVP to prevent slip of balloon by way of central waist during biphasic inflation.

Purpose

The purpose of this study was to evaluate safety and feasibility of Retrograde Inoue-Balloon for TAVI preparation.

Methods

From December 2013 to December 2019, 427 consecutive patients who performed TAVI for severe aortic valve stenosis, were retrospectively enrolled in Iwate Medical University. Of them, 227 (53%) patients (mean age 83±5 years, male 41%), underwent retrograde BAV before prosthetic valve implantation, comprised this study population. Retrograde BAV procedures were divided into two groups; patients used Inoue-Balloon without RVP and those did conventional balloon with RVP. The primary endpoint was defined as combined adverse events of 30-day mortality, cerebral infarction, and critical complications after BAV (aortic dissection, aortic rupture and cardiopulmonary arrest). The secondary endpoint was set as prolonged hypotension after BAV.

Result

Inoue-Balloon (IB) and conventional balloon (CB) were used for 73 patients (32%) and 154 (68%) patients, respectively. Both balloons were succeeded to through and expand of aortic valve in all cases. In the CB group, cardiopulmonary arrest occurred in 2.0% after BAV, cerebral infarction was observed in 3.9%, and 30-day death in 3.3%. On the other hand, no major complications were observed except one aortic dissection in the IB group. In logistic regression analysis adjusted by sex and age, the incidence of combined adverse events was significantly lower in the IB group (OR 0.17, 95% CI 0.009–0.917, P=0.037). Furthermore, the IB group had significantly a lower incidence of prolonged hypotension following BAV compared with CB group (4.1% vs 19.5%, p=0.002).

Conclusion

Balloon aortic valvuloplasty using retrograde Inoue-balloon without rapid ventricular pacing is safe and feasible, and may improve clinical outcomes of TAVI.

Funding Acknowledgement

Type of funding source: None

ARFRP1 functions upstream of ARL1 and ARL5 to coordinate recruitment of distinct tethering factors to the trans-Golgi network

SNARE-mediated fusion of endosome-derived transport carriers with the trans-Golgi network (TGN) depends on the concerted action of two types of tethering factors: long coiled-coil tethers of the golgin family, and the heterotetrameric complex GARP. Whereas the golgins mediate long-distance capture of the carriers, GARP promotes assembly of the SNAREs. It remains to be determined, however, how the functions of these tethering factors are coordinated. Herein we report that the ARF-like (ARL) GTPase ARFRP1 functions upstream of two other ARL GTPases, ARL1 and ARL5, which in turn recruit golgins and GARP, respectively, to the TGN. We also show that this mechanism is essential for the delivery of retrograde cargos to the TGN. Our findings thus demonstrate that ARFRP1 is a master regulator of retrograde-carrier tethering to the TGN. The coordinated recruitment of distinct tethering factors by a bifurcated GTPase cascade may be paradigmatic of other vesicular fusion events within the cell.

Comprehensive knockout analysis of the Rab family GTPases in epithelial cells

Rab small GTPases (∼60 genes in mammals) are the master regulators of intracellular membrane trafficking. Homma et al. establish a comprehensive collection of knockout epithelial cell lines for all the mammalian Rabs, revealing that Rab6 is required for basement membrane formation and soluble cargo secretion.

The Rab family of small GTPases comprises the largest number of proteins (∼60 in mammals) among the regulators of intracellular membrane trafficking, but the precise function of many Rabs and the functional redundancy and diversity of Rabs remain largely unknown. Here, we generated a comprehensive collection of knockout (KO) MDCK cells for the entire Rab family. We knocked out closely related paralogs simultaneously (Rab subfamily knockout) to circumvent functional compensation and found that Rab1A/B and Rab5A/B/C are critical for cell survival and/or growth. In addition, we demonstrated that Rab6-KO cells lack the basement membrane, likely because of the inability to secrete extracellular matrix components. Further analysis revealed the general requirement of Rab6 for secretion of soluble cargos. Transport of transmembrane cargos to the plasma membrane was also significantly delayed in Rab6-KO cells, but the phenotype was relatively mild. Our Rab-KO collection, which shares the same background, would be a valuable resource for analyzing a variety of membrane trafficking events.

A neurodevelopmental disorder caused by mutations in the VPS51 subunit of the GARP and EARP complexes

Golgi-associated retrograde protein (GARP) and endosome-associated recycling protein (EARP) are related heterotetrameric complexes that associate with the cytosolic face of the trans-Golgi network and recycling endosomes, respectively. At these locations, GARP and EARP function to promote the fusion of endosome-derived transport carriers with their corresponding compartments. GARP and EARP share three subunits, VPS51, VPS52 and VPS53, and each has an additional complex-specific subunit, VPS54 or VPS50, respectively. The role of these complexes in human physiology, however, remains poorly understood. By exome sequencing, we have identified compound heterozygous mutations in the gene encoding the shared GARP/EARP subunit VPS51 in a 6-year-old patient with severe global developmental delay, microcephaly, hypotonia, epilepsy, cortical vision impairment, pontocerebellar abnormalities, failure to thrive, liver dysfunction, lower extremity edema and dysmorphic features. The mutation in one allele causes a frameshift that produces a longer but highly unstable protein that is degraded by the proteasome. In contrast, the other mutant allele produces a protein with a single amino acid substitution that is stable but assembles less efficiently with the other GARP/EARP subunits. Consequently, skin fibroblasts from the patient have reduced levels of fully assembled GARP and EARP complexes. Likely because of this deficiency, the patient's fibroblasts display altered distribution of the cation-independent mannose 6-phosphate receptor, which normally sorts acid hydrolases to lysosomes. Furthermore, a fraction of the patient's fibroblasts exhibits swelling of lysosomes. These findings thus identify a novel genetic locus for a neurodevelopmental disorder and highlight the critical importance of GARP/EARP function in cellular and organismal physiology.

Disruption of FOXF2 as a Likely Cause of Absent Uvula in an Egyptian Family

This study investigated the genetic basis of an unusual autosomal dominant phenotype characterized by familial absent uvula, with a short posterior border of the soft palate, abnormal tonsillar pillars, and velopharyngeal insufficiency. Cytogenetic analysis and single-nucleotide polymorphism-based linkage analysis were investigated in a 4-generation family with 8 affected individuals. Whole exome sequencing data were overlaid, and segregation analysis identified a single missense variant, p.Q433P in the FOXF2 transcription factor, that fully segregated with the phenotype. This was found to be in linkage disequilibrium with a small 6p25.3 tandem duplication affecting FOXC1 and GMDS. Notably, the copy number imbalances of this region are commonly associated with pathologies that are not present in this family. Bioinformatic predictions with luciferase reporter studies of the FOXF2 missense variant indicated a negative impact, affecting both protein stability and transcriptional activation. Foxf 2 is expressed in the posterior mouse palate, and knockout animals develop an overt cleft palate. Since mice naturally lack the structural equivalent of the uvula, we demonstrated FOXF2 expression in the developing human uvula. Decipher also records 2 individuals with hypoplastic or bifid uvulae with copy number variants affecting FOXF2. Nevertheless, given cosegregation with the 6p25.3 duplications, we cannot rule out a combined effect of these gains and the missense variant on FOXF2 function, which may account for the rare palate phenotype observed.

The BLOC-3 subunit HPS4 is required for activation of Rab32/38 GTPases in melanogenesis, but its Rab9 activity is dispensable for melanogenesis

HPS4 biogenesis of lysosome-related organelles complex 3 subunit 2 (HPS4) is one of the genes whose mutations have been associated with Hermansky-Pudlak syndrome (HPS), characterized by ocular albinism and susceptibility to bleeding because of defects in the biogenesis of lysosome-related organelles such as melanosomes. HPS4 protein forms a BLOC-3 complex with HPS1, another HPS gene product, and the complex has been proposed to function as a guanine nucleotide exchange factor (GEF) for RAB32, a member of the Rab small GTPase family (Rab32), and Rab38 (Rab32/38-GEF) and also as a Rab9 effector. Although both Rab32/38 and Rab9 have been shown previously to be involved in melanogenesis in mammalian epidermal melanocytes, the functional relationships of these small GTPases with BLOC-3 remain unknown. In this study, we used site-directed mutagenesis to generate HPS4 mutants that specifically lack either Rab32/38-GEF activity or Rab9-binding activity and investigated their involvement in melanogenesis of melan-le cells (an HPS4-deficient melanocyte cell line derived from light ear mice). Melan-le cells exhibit a clear hypopigmentation phenotype, i.e. reduced expression and abnormal distribution of tyrosinase and reduced melanin content. Although re-expression of WT HPS4 completely rescued this phenotype, the Rab32/38-GEF activity-deficient HPS4 mutant failed to restore melanin content and tyrosinase trafficking in these cells. Unexpectedly, as WT HPS4, the Rab9 binding-deficient HPS4 mutant completely rescued the phenotype. These results indicate that activation of Rab32/38 by HPS4 (or BLOC-3) is essential for melanogenesis of cultured melanocytes and that Rab9 likely regulates melanogenesis independently of HPS4.

Abstract P2-09-33: Not presented

This abstract was not presented at the symposium.

A targeted sequencing panel identifies rare damaging variants in multiple genes in the cranial neural tube defect, anencephaly

Neural tube defects (NTDs) affecting the brain (anencephaly) are lethal before or at birth, whereas lower spinal defects (spina bifida) may lead to lifelong neurological handicap. Collectively, NTDs rank among the most common birth defects worldwide. This study focuses on anencephaly, which despite having a similar frequency to spina bifida and being the most common type of NTD observed in mouse models, has had more limited inclusion in genetic studies. A genetic influence is strongly implicated in determining risk of NTDs and a molecular diagnosis is of fundamental importance to families both in terms of understanding the origin of the condition and for managing future pregnancies. Here we used a custom panel of 191 NTD candidate genes to screen 90 patients with cranial NTDs (n = 85 anencephaly and n = 5 craniorachischisis) with a targeted exome sequencing platform. After filtering and comparing to our in‐house control exome database (N = 509), we identified 397 rare variants (minor allele frequency, MAF < 1%), 21 of which were previously unreported and predicted damaging. This included 1 frameshift (PDGFRA), 2 stop‐gained (MAT1A; NOS2) and 18 missense variations. Together with evidence for oligogenic inheritance, this study provides new information on the possible genetic causation of anencephaly.

The comparative anatomy of the folds, fossae, and adhesions around the duodenojejunal flexure in mammals

BACKGROUND

Anatomical knowledge of the duodenojejunal flexure is necessary for abdominal surgeries, and also important for physiologic studies about the duodenum. But little is known about the anatomy of this region in mammals. Here, we examined comparative anatomy to understand the anatomical formation of the duodenojejunal flexure in mammals.

MATERIALS AND METHODS

The areas around the duonenojejunal flexure were ob-served in mouse, rat, dog, pig, and human, and the anatomical structures around the duodenojejunal junction in the animals were compared with those in human.

RESULTS

The superior and inferior duodenal folds, and the superior and inferior duodenal fossae were identified in all examined humans. In pig, the structures were not clearly identified because the duodenum strongly adhered to the retroperitoneum and to the mesocolon. In mouse, rat, and dog, only the plica duodenocolica, which is regarded as the animal counterpart of the superior duo-denal fold in human, was identified, and other folds or fossae were not observed, probably because the duodenum was not fixed to the parietal peritoneum in those animals. Transection of the plica duodenocolica could return the normally rotated intestine back to the state of non-rotation in rat.

CONCLUSIONS

This study showed the anatomical similarities and dissimilarities of the duodenojejunal flexure among the mammals. Anatomical knowledge of the area is useful for duodenal and pancreatic surgeries, and for animal studies about the duodenum. (Folia Morphol 2018; 77, 2: 286-292).

Associations of aniseikonia with metamorphopsia and retinal displacements after epiretinal membrane surgery

PurposeTo determine the correlation of the degree of aniseikonia with the retinal displacements and metamorphopsia in patients that have undergone successful epiretinal membrane (ERM) surgery.MethodsSubjects were 28 eyes with an ERM in 28 patients. The New Aniseikonia Test (NAT) and M-CHARTS were used to quantify the degree of preoperative and postoperative aniseikonia and metamorphopsia. We also evaluated the distance between the intersections of 2 sets of retinal vessels situated vertically or horizontally by using spectral-domain optical coherence tomography (SD-OCT) images in 28 patients.ResultsThe vertical score of M-CHARTS (MV) was not significantly improved, but the horizontal score of M-CHARTS (MH) was significantly improved at 1 week, 1 month, and 3 months postoperatively. The preoperative NAT score was significantly correlated with the preoperative MH. The NAT score at 3 months was significantly correlated with the MH at 3 months and the MV at 3 months. The preoperative NAT score was significantly correlated with the ratio of the vertical retinal displacement at 1 month and at 3 months after surgery. However, the NAT scores did not improve significantly at any postoperative times.ConclusionsThe degree of aniseikonia was significantly correlated with the degree of metamorphopsia and the tangential displacement of the retina after ERM surgery. Aniseikonia is difficult to improve and metamorphopsia may be a more sensitive parameter to detect the functional recovery after successful ERM surgery.

M-INK, a novel tool for visualizing melanosomes and melanocores

Melanosome transfer from melanocytes to surrounding keratinocytes is one of the crucial but less well-characterized steps in the process of skin pigmentation. Although several markers have generally been used to detect melanosomes in melanocytes, no suitable markers for melanosomes that have been transferred into keratinocytes have ever been reported. The melanocore-interacting Kif1c-tail (M-INK) probe we developed and reported here specifically recognizes melanocores and thus makes visualizing melanosomes that have been incorporated into keratinocytes possible even in a fluorescent field. M-INK staining makes it possible to reconstruct 3D images of melanosome-containing keratinocytes, and thereby precisely localize melanosomes in keratinocytes.

The microfluidic lighthouse: an omnidirectional gradient generator

Studies of chemotactic cell migration rely heavily on various assay systems designed to evaluate the ability of cells to move in response to attractant molecules. In particular, the development of microfluidics-based devices in recent years has made it possible to spatially distribute attractant molecules in graded profiles that are sufficiently stable and precise to test theoretical predictions regarding the accuracy and efficiency of chemotaxis and the underlying mechanism of stimulus perception. However, because the gradient is fixed in a direction orthogonal to the laminar flow and thus the chamber geometry, conventional devices are limited for the study of cell re-orientation to gradients that move or change directions. Here, we describe the development of a simple radially symmetric microfluidics device that can deliver laminar flow in 360°. A stimulant introduced either from the central inlet or by photo uncaging is focused into the laminar flow in a direction determined by the relative rate of regulated flow from multiple side channels. Schemes for flow regulation and an extended duplexed device were designed to generate and move gradients in desired orientations and speed, and then tested to steer cell migration of Dictyostelium and neutrophil-like HL60 cells. The device provided a high degree of freedom in the positioning and orientation of attractant gradients, and thus may serve as a versatile platform for studying cell migration, re-orientation, and steering.

Vonoprazan prevents bleeding from endoscopic submucosal dissection-induced gastric ulcers

BACKGROUND

Vonoprazan, a potassium-competitive acid blocker, is expected to improve the healing of endoscopic submucosal dissection (ESD)-induced gastric ulcers compared with proton pump inhibitors (PPIs).

AIM

To compare the healing status of ESD-induced gastric ulcers and the incidence of post-ESD bleeding between subjects treated with vonoprazan for 5 weeks and those treated with PPIs for 8 weeks.

METHODS

Patients in the vonoprazan group (n = 75) were prospectively enrolled, whereas patients in the PPI group (n = 150) were selected for a 2:1 matched historical control cohort according to baseline characteristics including gastric ulcer size immediately following ESD, age, sex and status of Helicobacter pylori infection. Two controls per case of vonoprazan-treated group were matched with a margin of 20% in terms of ulcer size and a margin of 5 years in terms of their age.

RESULTS

Although a higher number of completely healed ulcers was observed in the PPI group (95/150, 63.3%) than that in the vonoprazan group (14/75, 18.7%; P < 0.001), the ulcer size reduction rates, which were 96.0 ± 6.7% in the vonoprazan group and 94.7 ± 11.6% in the PPI group, were not significantly different (P = 0.373). The post-ESD bleeding incidence in the vonoprazan group (1/75, 1.3%) was less than that in the PPI group (15/150, 10.0%; P = 0.01). The factors affecting post-ESD bleeding incidence were the type of acid secretion inhibitor (P = 0.016) and use of an anti-thrombotic agent (P = 0.014).

CONCLUSION

Vonoprazan significantly reduced post-endoscopic submucosal dissection bleeding compared with PPIs.

Multiple Types of Guanine Nucleotide Exchange Factors (GEFs) for Rab Small GTPases

Rab small GTPases are highly conserved master regulators of membrane traffic in all eukaryotes. The same as the activation and inactivation of other small GTPases, the activation and inactivation of Rabs are tightly controlled by specific GEFs (guanine nucleotide exchange factors) and GAPs (GTPase-activating proteins), respectively. Although almost all Rab-GAPs reported thus far have a TBC (Tre-2/Bub2/Cdc16)/Rab-GAP domain in common, recent accumulating evidence has indicated the existence of a number of structurally unrelated types of Rab-GEFs, including DENN proteins, VPS9 proteins, Sec2 proteins, TRAPP complexes, heterodimer GEFs (Mon1-Ccz1, HPS1-HPS4 (BLOC-3 complex), Ric1-Rgp1 and Rab3GAP1/2), and other GEFs (e.g., REI-1 and RPGR). In this review article we provide an up-to-date overview of the structures and functions of all putative Rab-GEFs in mammals, with a special focus on their substrate Rabs, interacting proteins, associations with genetic diseases, and intracellular localizations.

Abstract P5-08-47: Clinical outcome of pathological T1N0 breast cancer according to the hormone receptor and HER2 status and adjuvant therapy

Background: The outcome of T1N0 breast cancer is relatively good, however, a subpopulation of this stage has a high population of relapse. It is important to clarify the factors associated with the outcome in order to determine the adequate adjuvant systemic therapy for T1N0 breast cancer.

Aims: To investigate the prognosis of pathological T1N0 (pT1N0) breast cancer by receptor (estrogen receptor; ER, progesterone receptor; PgR, human epidermal growth factor receptor 2; HER2) status and adjuvant systemic therapy, and thus to identify the factors associated with the outcome.

Methods: Among 2164 women who underwent surgery for primary breast cancer in our department, 925 had pathological T1N0 tumors (130 T1a, 234 T1b and 561 T1c). The associations between clinicopathological characteristics, adjuvant therapy and relapse-free survival (RFS) were examined

Results: Of 908 patients with known hormone receptor (HR; ER and PgR) and HER2 status, 675, 79, 64 and 90 had HR+/HER2-, HR+/HER2+, HR-/HER2+ and HR-/HER2- (triple negative; TN) tumors, respectively. The prognosis of patients with T1c tumors was significantly poorer than that of the patients with T1a and T1b tumors (5-year DFS of T1a, T1b and T1c: 97.5%, 97.9%, 94.5%, p=0.0201). HR+/HER2- subtype was significantly associated with better prognosis than other subtypes (5-year DFS: 96.9% vs. 93.6%, p=0.0194). Patients younger than 40 year old or older than 74 years old had significantly shorter PFS (p=0.0039). Lymphovessel invasion (ly), high histological grade (HG2, 3) were associated with poor outcome in all cohort (p=0.0026, p=0.0356). In HR-positive tumors, ly, high HG and omission of the adjuvant endocrine therapy were associated with shorter RFS (p=0.0009, p=0.0306 and p=0.0016, respectively). Adjuvant chemotherapy was not associated with RFS regardless of HR and HER2 status. However, in T1c with nuclear grade (NG) 3 tumors, use of the adjuvant chemotherapy was associated better prognosis. The prognosis of patients with HER2+ tumors was not significantly different among patients with or without trastuzumab in this cohort.

Conclusion: In spite of the excellent prognosis of pT1N0 breast cancer, adjuvant endocrine therapy is important for patients with HR+ tumors. However, the use of adjuvant chemotherapy or trastuzumab did not significantly improve the prognosis. Thus, the indication of chemotherapy or anti-HER2 therapy should be determined in consideration of the several prognostic factors for pT1N0 breast cancer.

Citation Format: Tokunaga E, Akiyoshi S, Koga C, Nakamura Y, Taguchi K, Ishida M, Ohno S. Clinical outcome of pathological T1N0 breast cancer according to the hormone receptor and HER2 status and adjuvant therapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-47.

Abstract P4-12-02: Adjuvant trastuzumab improved the prognosis of HER2-positive early breast cancer: Single institutional cohort study from clinical practice

Background: Trastuzumab-containing regimens for the adjuvant treatment of human epidermal growth factor receptor 2 (HER2)-positive early breast cancer significantly improved the prognosis. However, most data showing the effects of trastuzumab come from clinical trials.

Aims: To evaluate the efficacy of the adjuvant trastuzumab in the clinical practice, the prognosis of HER2-positive early breast cancer was investigated according to the adjuvant treatment with or without trastuzumab.

Methods: Among 2548 women who underwent surgery for primary breast cancer in our department between 2000 and 2011, 315 patients had HER2-positive tumors. A total of 293 patients aged 75 or younger with invasive HER2-positive breast cancer were included in this study. The associations between clinicopathological characteristics, adjuvant therapy and relapse-free survival (RFS) were examined. The RFS was estimated using the Kaplan-Meier method, and independent predictors were assessed using proportional cox hazard models.

Results: 113 (38.5%) patients ware treated with chemotherapy alone (Cohort A), 100 (34.1%) patients were treated with chemotherapy and trastuzumab (Cohort B) and 80 (27.3%) patients received neither chemotherapy nor trastuzumab (Cohort C). The administration of adjuvant trastuzumab significantly increased in 2007. The prognosis of the patients treated in 2007-2011 was significantly better than that of patients treated in 2000-2006 (p=0.0011). The use of adjuvant trastuzumab was significantly associated with longer RFS (p=0.0286). The improvement of RFS by using trastuzumab was significant in node-positive patients. The patients in Cohort C had mainly node negative and small tumors. RFS of the patients treated of Cohort B was significantly more favorable than that of Cohort A. However, RFS of Cohort C was not statistically different from that of Cohort B, probably due to the early stage of Cohort C. In univariate analysis, larger tumor size (T2, 3), lymph node metastasis, lymphovessel invasion and absence of trastuzumab were related to relapse. In multivariate analysis, factors related to relapse were lymph node metastasis and absence of trastuzumab.

Univariate and multivariate analysis for relapse-free survivalFactorsUnivariate analysis Multivariate analysis  HR95% CIP valueHR95% CIP valueTumor sizeT2, T3 vs. T13.101.69-5.850.00021.820.87-3.950.1131LN meta.positive vs. negative4.372.26-8.84&lt;0.00012.831.26-6.490.0116Histological grade3 vs. 1, 20.770.42-1.440.4199   lypositive vs. negativ3.401.87-6.25&lt;0.00011.430.67-3.100.3538ERpositive vs. negativ0.930.50-1.650.7638   PRpositive vs. negativ0.970.50-1.760.8885   adjuvant chemotherapy 1.570.79-3.490.207   adjuvant trastuzumab 0.410.17-0.880.02070.410.16-0.900.0258LN meta.; lymph node metastasis, ly; lymphovessel invasion ER; estrogen receptor, PgR; progesterone receptor

Conclusions: Use of adjuvant trastuzumab improved the prognosis of HER2-positive early breast cancer in clinical practice.

Citation Format: Akiyoshi S, Ishida M, Koga C, Nakamura Y, Taguchi K, Ohno S, Tokunaga E. Adjuvant trastuzumab improved the prognosis of HER2-positive early breast cancer: Single institutional cohort study from clinical practice. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-12-02.

Abstract P6-07-10: Cytogenetic analysis of squamous cell carcinoma of the breast reveals inter- and intra-tumoral heterogeneity

Background: Squamous cell carcinoma (SCC) of the breast is a rare and generally aggressive disease constituting less than 0.1 % of all breast carcinomas. Although they have distinct morphological features, the origin and cytogenetic profiles of SCCs are still not well understood. In this study, five cases of SCC of the breast, three of which had an SCC component and an invasive or noninvasive ductal carcinoma of no special type (NST) component, were analyzed to evaluate their cytogenetic inter- and intra-tumoral heterogeneity.

Methods: Using a pathological database of approximately 3,000 patients with breast cancer, five patients with SCC were identified. Their medical records were retrospectively reviewed to obtain clinicopathological, radiological, therapeutic and prognostic information. The area largely consisting of the SCC component was macro-dissected from five 10 μm-thick sections and tumor DNA was extracted using the QIAmp DNA Mini Kit (Qiagen). Three cases contained a component of invasive or noninvasive ductal carcinoma of NST as well as an SCC component, and tumor DNA from NST components were also extracted as described above. Tumor DNA from each case were used for array comparative genomic hybridization (aCGH) analysis using a high-density oligonucleotide microarray (Agilent® SurePrint G3 8x60k microarray) and the cytogenetic profiles of SCC components were compared with each other and in three of the five cases with their paired NST components.

Results: Sufficient amounts of DNA were obtained for aCGH analysis with an average of 0.78 μg (0.39–1.35 μg). The quality of the aCGH was acceptable, as judged by the mean derivative log ratio spread (DLRSpread) of 0.45 (0.20–0.55), which estimates the log ratio noise by calculating the spread of log ratio differences between consecutive probes along all chromosomes. The cytogenetic profiles of SCC components showed large inter-tumoral heterogeneity with between 2 and 160 copy number alterations per case and no common copy number alterations were found among cases. Meanwhile, cytogenetic profiles were almost identical between paired SCC and NST components,. However, in one case, a large number of copy number aberrant (CNA) regions were detected in the SCC component compared with the NST component and all aberrations in the NST component were also present in the SCC component, which implies that the SCC component originated from the NST component. There were no common SCC-component-specific aberrations in the three cases with NST components.

Conclusion: These results demonstrate the degree of cytogenetic inter- and intra-tumoral heterogeneity in SCC of the breast. The comparison of cytogenetic profiles in one case indicated that the SCC component originated from the NST component.

Citation Format: Oikawa M, Igawa A, Ishida M, Nakamura Y, Nishimura S, Koga C, Akiyoshi S, Koi Y, Taguchi K, Ohno S, Tokunaga E. Cytogenetic analysis of squamous cell carcinoma of the breast reveals inter- and intra-tumoral heterogeneity. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-07-10.

Cholestatic Liver Injury After Biliary Reconstruction Impairs Transplanted Islet Viability and Function

Islet autotransplantation following total pancreatectomy differs from allograft transplantation with respect to the requirement of biliary reconstruction. Although it is known that careful consideration should be given to postoperative cholestatic liver injury after biliary reconstruction, its direct effects on transplanted islets have not been completely elucidated. In this study, we developed a murine model of postoperative cholestatic liver injury after biliary reconstruction with islet autotransplantation that involved syngeneic intraportal islet transplantation into chemically induced diabetic mice and common bile duct ligation. We assessed the viability and function of the transplanted islets. The impaired viability of transplanted islets and increased blood glucose levels indicated restoration of the diabetic state after common bile duct ligation in this murine model. Furthermore, impaired islet viability and function occurred earlier in the transplanted islets than in the surrounding liver tissues, which was consistent with the faster and higher expression of oxidative stress markers in the transplanted islets. Transplanted islets may be more vulnerable to oxidative stress caused by cholestatic liver injury than the surrounding liver tissue. Therefore, patients should be intensively managed after total pancreatectomy with islet autotransplantation to preserve viability and function of the transplanted islets.

Enhanced ultrasonography using a nano/microbubble contrast agent for islet transplantation

Recent basic and clinical studies have assessed the use of highly sensitive imaging modalities for visualizing transplanted islets. We investigated the utility of enhanced ultrasonography, combined with fluorescent acoustic liposome nano/microbubbles (FALs), for evaluating angiogenesis and the endocrine function of transplanted islets. BALB/c mice were classified into three groups: Diabetic mice that underwent syngeneic islet transplantation into the subrenal capsule and achieved normoglycemia (Tx group); those that failed to achieve normoglycemia (Tx-DM group); and those not receiving any treatment (DM group). Mice were examined by FAL-enhanced high frequency ultrasonography. The echogenicity of the islets increased rapidly within the first minute after injection of FALs and remained at a higher level in the Tx group, while small increases were observed in the other two groups. In histological assessments, fluorescently stained erythrocytes could be seen in and around the transplanted islets, indicating that the transplanted islets were enhanced by infusion of FALs via vessel networks between the engrafted islets and tissue. Furthermore, the echogenicity correlated significantly with endocrine parameters, including blood glucose (BG), serum insulin, and the BG change in the glucose tolerance test. In conclusion, the echogenicity of the islets under FAS-enhanced ultrasonosonography correlated with the endocrine status of transplanted islets.

Vitamin D metabolism in hypophosphatemic vitamin D-resistant rickets

Plasma levels of 1,25-(OH)2-D were low in children with hypophosphatemic vitamin D-resistant rickets (HVDRR), but increased after very large doses of 1 alpha-OH-D3. These results suggest that the metabolism of 1,25-(OH)2-D is accelerated in HVDRR. In addition, the lower level of plasma 1,25-(OH)2-D in untreated HVDRR was correlated with the lower level of serum phosphate and renal threshold phosphate concentration (TmP/GFR). The administration of 1 alpha-OH-D3 to the patients with HVDRR could enhance the renal threshold phosphate concentration.

Rab1A regulates anterograde melanosome transport by recruiting kinesin-1 to melanosomes through interaction with SKIP

Melanosomes are lysosome-related organelles in melanocytes that are transported from the perinucleus to the cell periphery by coordination between bidirectional (anterograde and retrograde) microtubule-dependent transport and unidirectional actin-dependent transport. Although the molecular machineries that mediate retrograde transport and actin-dependent transport have already been identified, little is known about the anterograde transport complex on microtubules in mammalian cells. Here we discovered that small GTPase Rab1A on melanosomes recruits SKIP/PLEKHM2 as a Rab1A-specific effector and that Rab1A, SKIP, and a kinesin-1/(Kif5b+KLC2) motor form a transport complex that mediates anterograde melanosome transport in melanocytes. Interestingly, Arl8, Arf-like small GTPase that also interacts with SKIP, is specifically localized at lysosomes and regulates their anterograde transport in melanocytes. Our findings suggest that the anterograde microtubule-dependent transport of melanosomes and lysosomes are differently regulated by independent cargo receptors, i.e., Rab1A and Arl8, respectively, but that a SKIP–kinesin-1 mechanism is responsible for the transport of both.

Longitudinal spin Seebeck effect: from fundamentals to applications

The spin Seebeck effect refers to the generation of spin voltage as a result of a temperature gradient in ferromagnetic or ferrimagnetic materials. When a conductor is attached to a magnet under a temperature gradient, the thermally generated spin voltage in the magnet injects a spin current into the conductor, which in turn produces electric voltage owing to the spin-orbit interaction. The spin Seebeck effect is of increasing importance in spintronics, since it enables direct generation of a spin current from heat and appears in a variety of magnets ranging from metals and semiconductors to insulators. Recent studies on the spin Seebeck effect have been conducted mainly in paramagnetic metal/ferrimagnetic insulator junction systems in the longitudinal configuration in which a spin current flowing parallel to the temperature gradient is measured. This 'longitudinal spin Seebeck effect' (LSSE) has been observed in various sample systems and exclusively established by separating the spin-current contribution from extrinsic artefacts, such as conventional thermoelectric and magnetic proximity effects. The LSSE in insulators also provides a novel and versatile pathway to thermoelectric generation in combination of the inverse spin-Hall effects. In this paper, we review basic experiments on the LSSE and discuss its potential thermoelectric applications with several demonstrations.